In winding a linear member around a deflection yoke (also called a bobbin) it is necessary that the linear member be wound orderly along winding grooves formed in the deflection yoke. However, if the linear member used is circular in section, it is dispersed and becomes unstable positionally, thus resulting in that overlap of the linear member is apt to occur. Once there occurs overlap, the winding thickness of the linear member increases and therefore the diameter of the deflection yoke must be increased accordingly, thus causing lose of the deflection efficiency.
In view of the point mentioned above, it has recently been proposed to use a flat linear member having a flat section. In this case, there is used a flat linear member having a width matching the width of each winding groove formed in a deflection yoke, and by merely stacking the linear member at the same place it is possible to wind it around the deflection yoke in an orderly manner without dispersion.
Examples of the flat linear member include such a flat linear member assembly W1 as shown in FIG. 22A, which is obtained by assembling and fusion-bonding linear members 11 of a circular section into a flat shape, and such a flat linear member assembly W2 as shown in FIG. 22B, which is obtained by assembling and fusion-bonding linear members 12 of a square section into a flat shape.
When a linear member is wound round a deflection yoke, a single winding thereof causes the linear member to be twisted once. Winding of a flat linear member is as shown in a conceptual diagram of FIG. 23. As shown therein, when a flat linear member W is wound round a deflection yoke, it is bent at four corner portions and is twisted 90 degrees at each of the corner portions. It follows that one round results in a twist of 360 degrees of the linear member W about its longitudinal axis. This twist gives rise to no special problem in the use of a linear member having a circular section, but must be eliminated in the case of winding a flat linear member in an orderly manner.
Automatic winding of a linear member around a deflection yoke also requires the twist eliminating work.
The present invention has solved the above conventional problem. It is an object of the invention to permit a flat linear member as a deflecting coil to be wound automatically around a deflection yoke without causing twist of the linear member.
It is another object of the present invention to realize automatic winding of a flat linear member in high efficiency and high accuracy without causing twist of the linear member.
It is a further object of the present invention to utilize the equipment and method of the invention for wide-angle deflection or for improving the deflection efficiency of high-frequency scan.